During which prenatal developmental period is the probability of a structural defect the greatest?

A. Identity foreclosure: Foreclosure is commitment without prior crisis/exploration, so it does not fit someone who has undergone a crisis.
B. Identity diffusion: Diffusion is marked by neither crisis nor commitment, so it contradicts the description.
C. Identity achievement: Identity achievement is reached after a period of crisis/exploration followed by making a committed choice; this matches “undergone a crisis and made a commitment.”
D. Identity moratorium: Moratorium indicates active exploration/crisis without having yet made a commitment, so it does not fit someone who has already made a commitment.

A. cross-sectional: Cross-sectional studies compare different age groups at one time point rather than following the same individuals over time.
B. naturalistic observation: Naturalistic observation is a method of observing behavior in real settings but does not specify a long-term follow-up of the same cohort.
C. longitudinal: Longitudinal studies follow the same group of individuals across multiple time points (e.g., infancy into adulthood), matching Dr. Chang’s description.
D. experimental: Experimental studies manipulate variables and assign participants to conditions, not simply following a group over many years.