According to the federal regulations, which of the following studies meets the definition of research with human subjects?

A. A researcher conducts a comparison of the comments made in a publicly available blog and the blogger's comments on a similar topic in a weekly magazine.
B. A researcher sets up a meeting with the superintendent of a large and diverse public school system to get data about the ethnic composition of the school system and the number of students receiving free lunches.
C. A cognitive psychologist enrolls undergraduate students for a computer-based study about the effect of mood on problem solving behaviors.
D. Undergraduate students in a field methods class are assigned a research question and asked to interview another classmate, to be followed by a class discussion on interview techniques.

Awoman was found strangled in the basement of her home where she lived with her husband. the crime scene was processed and investigators left. the next day, the medical examiner reported that a scalloped, woven belt was used to strangle the victim. the police asked the husband to search the house again to look for such a belt and he agreed. a belt was found that matched marks on the victim. the man was arrested. his attorney made a motion that the belt be excluded from the evidence as he contended that the search was not legal. which statement is true? a. the belt should be excluded because the search was not legal. the police did not obtain a search warrant, as needed according to the fourth amendment to the u.s. constitution. b. the belt is admissible because the man gave his consent to the second search. c. the belt should be excluded because the search was not legal. the police did not obtain a search warrant, as need according to michigan v. tyler. d. the belt is admissible as evidence, according to mincey v. arizona.