People may behave differently in artificial situations than they would in the "real world". this poses a particular problem for researchers using a. questionnaires. b. content analysis. c. replication. d. laboratory experiments

Option D, laboratory experiments.

Explanation:

Whenever a researcher is posed to study about any artificial situation, it becomes easy for them to study it through experimentation. For artificial situations, researcher get the freedom to make changes in the variables. Also, they can introduce control variables. While on the other hand studying a real scenario would require designing of an objective based questionnaire and then conduction a survey  to get real inputs.

Hence, option D is correct

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.