Standing on launch you see a rain shower approaching. Do you take off?
D is the only safe answer. You can never be sure that you have landed before the rain arrives, so C is risky. B is only partly true for light rains, but again you're taking a risk. A is not true, although flying in cloud is illegal in many countries.

What part is indicated by C (the orange line)?
A diagonal rib connects the upper left corner of a cell with the lower right, or sometimes runs across two or more cells.
This allows the use of fewer lines, reducing the weight and drag of the paraglider.

How tight does the chest strap of the harness need to be?
A short distance beween the karabiners results in a stable flight but enhances the risk of twisting, for example after a collapse.
A large distance between the karabiners results in a higher sensitivity to weight shift but also to more dynamic reactions of the paraglider.

When is the best time to put your legs down during the landing approach?
D is the safest option. The others are either uncomfortable and unwanted because you can't use weightshift anymore, or unsafe if you are too late and land on your bum risking a back injury.

A paraglider glides down through the air. But at what speed?
These are all speeds relative to the air!

How tight do you need to pull the leg straps of the harness?
The tightness of the leg straps does not influence the flying properties of the paraglider.
When the leg straps are too loose, after take-off you will find yourself hanging low under the seat and it's more difficult to get in the harness.
Too tight will hinder your movements during take-off, depending on the harness design. In some harnesses it will prevent you from getting into the seat fully.

What happens when you brake a paraglider so much that the air speed falls below the minimum speed of about 25km/h?
The photo shows what happens when you pull so much brake that the air speed of the paraglider falls below its minimum speed. The glider stalls. Therefore we sometimes call the minimum speed of a paraglider the stall speed.
Don't do this while flying! Unless you are on an SIV- or acrocourse.
Older gliders can also enter a deep stall when you brake too much - see the chapter on Aerodynamics.

What happens when you fly too slowly?
Below the minimum speed or stall speed, the wing stops flying and will descend straight down like a parachute. This is a very unstable situation and often leads to a spin or stall.
See the chapters on Aerodynamics (stalls) and Advanced flying.

What is the weight of the fabric used to make paraglider canopies? (g/m2)?
Very light fabric strong enough for paragliders can be as light as 25g/m2. Very strong and heavy fabric weighs 40g/m2 or more.
At around 35g/m2, you can calculate that the weight of the fabric of just the top and bottom sail of a 25m2 canopy is a bit less than two kilos.

What do you do when you can't hear the instructor over the radio during a flight?
B is correct, A and C are nonsense of course.
Answer D is the second best choice in case your mind goes blank, you panic and you don't know what to do. It's better to do nothing in that case.
Your result is shown above.