Is the data set approximately periodic? if so, what are the period and amplitude?

the tables show the value of a stock, in dollars, each week for 20 weeks.

identify whether the data set is approximately periodic and, if so, determine the period and amplitude.

question 2 options:

the data set is not approximately periodic.

the data set is approximately periodic with a period of 5 and an amplitude of about 3.

the data set is approximately periodic with a period of 10 and an amplitude of about 6.

the data set is approximately periodic with a period of 10 and an amplitude of about 11.