The correct answer is: E. fee.amount[0] = fee.amount[0] + 2;
Option A: amount[0] = amount[0] + 2; will increase the value stored in the first element of the amount array by 2.
Option B: amount, fee[0] = amount, fee [0] + 2; is incorrect because it assigns the value of amount to the variable fee. The value of fee[0] is not changed.
Option C: feelnfo.amount[0] = feelnfo.amount[0] + 2; is incorrect because it attempts to access the amount property of the variable feelnfo. The variable feelnfo does not have an amount property.
Option D: fee[0].amount = fee[0].amount + 2; is incorrect because it attempts to access the amount property of the element at index 0 of the fee array. The element at index 0 of the fee array does not have an amount property.
Option E: fee.amount[0] = fee.amount[0] + 2; is correct because it increases the value stored in the first element of the fee array by 2.