During an engagement, a penetration tester receives a list of target systems and wants to...

Comprehensive and Detailed Explanation:

f.readlines() returns each line including trailing newline and any extra fields (labels). Given targets.txt lines contain URL followed by a label separated by whitespace, target will contain "http://10.10.6.4/ CompTIA-MR1\n ". Concatenating that directly with api yields an invalid URL. Splitting the line on whitespace and taking the first element (target.split(" ")[0] or better target.split()[0]) extracts just the URL (http://10.10.6.4/ ) before building url = target + api. This removes the descriptive label and newline so the resulting url is valid.

Why not the others:

A: Changes API format incorrectly.

C: Stripping http:// would make an invalid absolute URL for requests.post.

D: Passing api as the second positional parameter to requests.post is wrong (it expects data= or json=), and doesn’t fix the problem of extra label text in target.

PT0-003 mapping: Domain 4 — robust parsing and input sanitization when reusing scripts.