Memory profile of parLapply()

You are calculating correlations between stock prices of tech companies. You have a list of data frames ls_stocks. Each data frame contains weekly stock price data. You want to apply a function, calc_cor() to each element of ls_stocks using parLapply(). You decided to profile your code using profvis() to check on the memory usage.

This is the output you get:

Which of the following options are true?