Answer:
Longitudinal study
Step-by-step explanation:
Information is collected over extended periods of time in a longitudinal study, but in cross-sectional, natural observation, and experimental studies, information is collected over short periods of time or in one time only. Based on the choices given, this type of study would be a longitudinal study.
The answer is C. 1
You can just plug in the different answers for x and see which one equals zero.
F(1) = 1 + 4 + 1 - 6 = 0