A) The correct answer to the first question about the type of error within the sequence of characters written in a programming language is syntax error.
For the code revision question, the correct code to incorporate the given policies would be:
if age > 40:
if category == 'C':
# 55 percent discount
discount = discount + (0.55 * amount)
This implementation checks if the age is greater than 40 and only applies a discount for category 'C', in accordance with the provided specifications. All discount policies for category 'A' are revoked.
A) For the final question regarding accessing an established collection of resources to acquire pre-written code, the correct answer is library.