Answer:
The last option is the correct one.
Step-by-step explanation:
This is how the verb Aller conjugates:
je vais
tu vas
il/elle/on/qui va
nous allons
vous allez
ils/elles vont
In this case the noun is "vous" so the participle is "allez". Then the next blank is a negation so you ALWAYS have to use "ne" and "pas". You put the conjugated verb inbetween the "ne" and "pas" so it will be "ne vais pas". (its vais because the noun is "je"). Aller basically means "to go/will/going to". The last blank is translated as "I _______ a walk." which makes no sense unless you add a verb. To translate the last option it is "vais faire" which is "you(plural) do/make". I know it doesn't really make sense but sometimes french words don't exactly translate to english well. But when you put together the whole thing this is how it translates "A; Hello Mrs. Dupont are you going to the supermarket today? B: No, I will not go over there, I will go on a walk." Now the entire paragraph makes sense.
-I hope this helped you :)