QUESTION 4 Which statements are true? The number of iterations a while loop will execute is known in advance. The number of iterations a while loop will execute is not known in advance. Failure to update a test variable can cause an infinite loop. O A while loop is an indefinite loop A while loop is a definite loop. QUESTION 5 Consider the following code. You want to create a vector variable two_power_k that contains values of 2k starting with 21 until the sum of the vector elements becomes larger than 20 Which line of code is the most appropriate for filling the blank space after k k 1? total 0 k = 0; while total20 total sum(two power_k) end A two-power-k(k) = 24k two_power_k 2k two_power_k- two_power_k+1 two-power-k(k) = two-power-k +1