Tucker is a graduate student who is studying identity formation. He selects a group of 5-year-olds, a group of 10-year-olds, and a group of 15-year old, and interviews each group, asking them what they plan to be when they finish school. In this example, Tucker is using

B). A Cross-sectional research design.

Explanation:

A cross-sectional research design is demonstrated as a kind of observation study that involves the study and analysis of a representative subset from the population at a particular point of time.

In the given example, Tucker is employing 'cross-sectional research design' as he selects a representative subset('a group of 5-year-olds, a group of 10-year-olds, and a group of 15-year old) from the population at the same time for study and analysis(by interviewing them) . This implies that Tucker adopts a 'cross-sectional research design.'

on december 1, 1774, the continental association was created to boycott all contact with british goods. by reversing the economic sanctions placed on the colonists, the delegates hoped britain would repeal its intolerable acts.

they all focused on themes about the inevitability of death.