Hello, first you look at the number of tricycle you need to sell in order to make $50.00. This would be

tricycles. We round this up to 13 since we do not have half a tricycle.
Knowing this, you won't actually need all the other given parts since you only need to know that you need 2 pedals to make a tricycle. Multiply these pedals by 13 you'll get:

.
ANSWER: B. You would need 26 pedals in order to make $50.00