An investor has two accounts, Account P and Account Q. Account P earns an annual simple interest rate of 4%, and Account Q earns an annual simple interest rate of 6%. In one year, the total interest earned from both accounts was $1,200. The equation represents this situation. Which of the following is the best interpretation of in this context?
The total amount of interest earned from Account P
The principal amount invested in Account P
The interest rate of Account P
The principal amount invested in Account Q
