Thanks for your patience with the reply.

Let's briefly review all the answer choices here to make sure things make sense.

D is true should be fairly straightforward, comparing the g = 3.7 on Mars that is given to the g = 9.81 on Earth.

A vs B hopefully makes sense as well, since in general gravity between two objects A and B is $\dfrac{G\cdot m_a\cdot m_b}{r^2}$ where $r$ is the distance between them, in fact the weight (equals force of gravity) is increasing as the lander is descending. Hence, B is true and A is false.

Note: On the exam, I'd argue that we've now solved the problem. Clearly B and D are true, so we have our two true answers and can move on. Answer choice C is a little weird, so we can be fairly confident ignoring it.

Continuing, what if we want to understand choice C a little more?

First off we have to clarify "while it is landing". Under one interpretation, the vehicle is landing as it is descending through the sky (that is, not touching the ground). While it is off the ground, there is no normal force exerted by Mars, so this doesn't make sense as an answer choice either (as the vehicle still has a weight as there is a force of gravity.

Lastly, (which I assume is your actual question as it relates to your screenshot. What happens when the lander is actually on the ground? Here the vehicle doesn't fall into the ground, so there is a normal force that counterbalances the force of gravity (weight). Hence, there are many scenarios of the normal force equaling the weight when the vehicle is on the surface. However, all of these scenarios assume that the vehicle is not accelerating, on flat ground, etc. For example, if the vehicle is accelerating/decelerating (for example slowing down as it is touching the surface, think about your knees bending after jumping in the air, etc.) the sum of the forces is NOT = 0, so the normal force is not equal to the force of gravity / weight.

Hope this helps a bit! Let us know if there are any additional questions.