A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches.

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors results in 83 who indicate that they recommend aspirin. The value of the test statistic in this problem is approximately equal to:

   a. - 4.12

   b. - 2.33

   c. - 1.86

   d. - 0.07