Answer
(c) $-1.5299$
Work Step by Step
Step 1: Ensure that the calculator is in radian.
Step 2: $\sec 4=\frac{1}{\cos 4}$
Step 3: Type $\frac{1}{\cos 4}$ into the calculator and press enter.
Step 4: Rounding out the answer to 4 decimal places,
$\frac{1}{\cos 4}\approx-1.5299$.
Step 5: Therefore, the answer is option (c).