use aapl.cev & googl.cav for the following question. These two datasets have the following columns: Date: Month end date Close: closing price Dividends: dividend in $ to share holders. Keep in mind not every company gave dividends in sample period. Stock. Splits: if no stock split happened, value is 0, if a stock split happened then one stock was split into the value provided in this column. You may not have to use this column as closing price has already been adjusted for stock split. Keep in mind not every company split it's stock in sample period. A. Please calculate simple returns for AAPL and GOOGL stocks for all months for 2020, 2021 and 2022. Report the month and year for each stock in which they gave maximum simple return. In case of a tie, report earliest month. (6 points) Do not forget to remove NA values as necessary. shift function may help in calculating simple return but you are free to use your method/function in R. Here is a quick reference: (https://www.rdocumentation.org/packages/data.table/versions/1.11.4/topics/shift)