please refer to the image below and kindly please make a clear answer. thank you

Below are researchable problems. Identify the most appropriate method/s of gathering data to be used. Explain and justify your answer. a. A study to identify the factors being considered by the consumers in buying shoes, clothes, and personal accessories b. A study to find out if a new brand of the drug effectively cures tuberculosis. c. Researches to determine the mortality rate from 1990 to 1998. d. An approach to finding out the relationship between age and mental ability. e. A study to determine the study habits of third-year high school students in Manila f. An inquiry on the average allowance of second-year high school students in a certain school