Step-by-step Solution:

We will calculate the sum step-by-step:\[\] Step 1: Add (39798 + 3798) \[\] 39798 + 3798 = 43596 \[\] Step 2: Add (43596 + 378) \[\] 43596 + 378 = 43974 \[\] Final Answer:\[\] The correct sum is (43974). \[\] \[\] Correct Answer: (b)