[Solved] The period when major systems, organs, and structures are formed is called the period of the A) ovum. B) fetus. C) embryo. D) zygote. Relationship Infidelities: Acts of being unfaithful or betraying a partner's trust within a romantic relationship. Cheating: Cheating involves behaving dishonestly or unfairly in order to gain an advantage, especially in a context like academics, sports, or relationships. Exotic Becomes Erotic: A theory suggesting that individuals become erotically attracted to the unfamiliar, or those who are different from themselves and their early environment. Daryl Bem: A prominent psychologist known for his work in the areas of personality, sexual orientation, and the self-perception theory which suggests that people develop their attitudes and emotions by observing their own behavior.