Step 1:

Consider option (a).

The function is $\"\"$ .

If $\"\"$ , then the function $\"\"$ is said to be an odd function.

$\"\"$

Consider option (b).

The function is $\"\"$ .

If $\"\"$ , then the function $\"\"$ is said to be an odd function.

$\"\"$

Step 2:

Consider option (c).

The function is $\"\"$ .

If $\"\"$ , then the function $\"\"$ is said to be an odd function.

$\"\"$

Consider option (d).

The function is $\"\"$ .

If $\"\"$ , then the function $\"\"$ is said to be an odd function.

$\"\"$

Therefore, $\"\"$ is an odd function.

Option (d) is an odd function.