Question

In your study unit, a relationship is compared to a car to point out that
a. any relationship can be "driven" too fast or too slow.
b. past relationships are like old cars.
c. a new relationship gets more attention than an old one.
d. relationships require regular maintenance.

Answer 1

It would be best to have a context for this question, but from what I can see the best answer is the last one:  that relationships require regular maintenance. All the other options are not very helpful advice about how to have a healthy relationship.