State and explain 2 method of data collection

focus groups and interviews

Explanation:

focus groups are groups interviews that focus on one or more surveys or products were the guests of the group get to vote to show what they would use or what they are most likely to do.

interviews are individual questions asking and interviewing and are prefered for applying for jobs and in many cases questioning suspects of a crime.

both methods are quite affective when it comes to collecting data

b. shallow would be my guess

d.) the area was once ocean