Professor Juarez is interested in measuring the difference in spatial ability between people of different ages. He intends to give these individuals a spatial abilities test during the next year. Professor Juarez will be conducting:

a cross sectional study

Explanation:

Cross-sectional study: In psychological research, the term "cross-sectional study" is also referred as transverse study, cross-sectional analysis, and prevalence study and is described as one of the different types of observational studies that generally analyzes various data from a particular population including participants or else a 'representative subset' during a particular point in time.

In the question above, Professor Juarez will be conducting a cross-sectional study.

parable of the tares

explanation:

i would say b. research typically uses a variety of sources