Ca n't be sure about that , though . One step at a time ... " Andy watched , fascinated , and did n't interrupt again . Castin worked with his laptop battery and the elevator 's wiring , cursing a lot as he went .

Based on the preceding passage, choose your answer for question Why did Andy watch ?
Choose your answer from: (1). He was fascinated .; (2). He was curious about all the cussing .; (3). Because Castin worked with his laptop .; (4). Because of the elevator 's wiring .;
The answer is:
(1).