pls help with hw question

Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2). . . ... (a) To compute probabilities regarding the sample mean using the normal model, what size sample would be required? Choose the required sample size below. A. The sample size needs to be greater than 30. its O B. The normal model cannot be used if the shape of the distribution is unknown. O C. Any sample size could be used. O D. The sample size needs to be less than 30. (b) What is the probability that a random sample of n = 45 oil changes results in a sample mean time less than 10 minutes? The probability is approximately rary (Round to four decimal places as needed.)