Final answer:
All of the listed errors, divide by zero, arithmetic overflow, and unsuccessful memory allocation, are considered synchronous errors because they occur at a specific point in the program execution and are directly tied to the program instructions.
Step-by-step explanation:
The question asks which of the following errors is synchronous: a. Divide by zero. b. Arithmetic overflow. c. Unsuccessful memory allocation. d. All of the above. In computing, synchronous errors are those that occur during the execution of a program and are directly related to a specific program instruction or process state. They are typically deterministic and reproducible given the same program state and inputs.
Divide by zero and arithmetic overflow are classic examples of synchronous errors because they occur as a direct result of the execution of a specific computation operation at runtime. An unsuccessful memory allocation, on the other hand, would usually be considered synchronous as well, because it fails during the attempt to allocate memory, which is an operation requested by the program at a specific point in time.
In conclusion, the correct answer is d. All of the above. Each of these errors is synchronous because they occur in a predictable execution point and are directly tied to the instructions being executed by the program.