Martha studies all the kinds of leaves she can find in order to understand what leaves have in common. martha's research is employing reasoning.
a. deductive
b. 20-20 hindsight
c. syllogistic
d. inductive

d. inductive

Explanation:

d. inductive

An approach in which specific calculation, investigations, or work etc is done related to the topic and a generalized conclusion is framed based on investigation for the same is known as inductive approach or inductive reasoning.Thus, studying about all kinds of leaves shows that Martha has specifically investigated types of leaves in order to distinguish between all the types of leaves.

Hence, in the above case we can Martha can use  inductive research reasoning to find what leaves have in common.