Step 1: Understanding the Concept:
Four chemotherapy drug classes need to be matched with one representative drug each, so the approach is to recall a prototype drug and its mechanism for every class listed.
Step 2: Key Formula or Approach:
Go class by class: alkylating agents add alkyl groups to DNA, platinum analogs form DNA crosslinks, antimetabolites mimic natural nucleotides to block synthesis, and EGF receptor inhibitors block growth factor signaling.
Step 3: Detailed Explanation:
Alkylating agents are represented here by Chlorambucil, which adds alkyl groups to DNA and interferes with replication, giving pair (1)-(S).
Platinum analogs are represented by Cisplatin, which crosslinks DNA strands and blocks synthesis, giving pair (2)-(Q).
Antimetabolites are represented by 5-fluorouracil, which mimics a natural pyrimidine and blocks nucleotide synthesis, giving pair (3)-(P).
EGF receptor inhibitors are represented by Cetuximab, a monoclonal antibody that blocks epidermal growth factor receptor signaling, giving pair (4)-(R).
Combining these four pairs gives (1)-(S), (2)-(Q), (3)-(P), (4)-(R).
Step 4: Final Answer:
The correct match is (1)-(S), (2)-(Q), (3)-(P), (4)-(R).