Step 1: Write \(\tan x\) in sine-cosine form.
Given,
\[
\frac{\cos x}{1+\sin x}+\tan x
\]
Using
\[
\tan x=\frac{\sin x}{\cos x},
\]
we get
\[
=
\frac{\cos x}{1+\sin x}+\frac{\sin x}{\cos x}
\]
Step 2: Rationalize the first term.
Multiply numerator and denominator of
\[
\frac{\cos x}{1+\sin x}
\]
by
\[
1-\sin x
\]
Then,
\[
=
\frac{\cos x(1-\sin x)}
{(1+\sin x)(1-\sin x)}
+\frac{\sin x}{\cos x}
\]
Step 3: Simplify the denominator.
Using
\[
(1+\sin x)(1-\sin x)=1-\sin^2 x,
\]
we get
\[
=
\frac{\cos x(1-\sin x)}
{\cos^2 x}
+\frac{\sin x}{\cos x}
\]
\[
=
\frac{1-\sin x}{\cos x}
+\frac{\sin x}{\cos x}
\]
Step 4: Combine the fractions.
\[
=
\frac{1-\sin x+\sin x}{\cos x}
\]
\[
=
\frac{1}{\cos x}
\]
Step 5: Convert into secant form.
Since
\[
\sec x=\frac{1}{\cos x},
\]
therefore,
\[
=
\sec x
\]
Step 6: Match with the options.
The simplified expression is
\[
\sec x
\]
Step 7: Final conclusion.
Hence,
\[
\boxed{\sec x}
\]