Answer:
d. involves analyzing end-user business requirements in order to refine project goals
Explanation:
In the software development life cycle, the implementation stage is the stage where the computer programmers begin the actual coding of the application required by the end-user. At this stage, the developer takes into account the needs and specifications of the customer.
For example, if the end-user wants a software application that can track payment records, the researcher at this stage begins using the right software to code programs that can effect this function.
Answer:

Explanation:
The statements are logically equivalent if they have the same truth tables. So let´s use truth tables in order to determine if they are logically equivalent or not:
The picture that I attached you shows the truth table for each case. As you can see in the highlight columns:

They are logically equivalent because they have exactly the same truth values between each other. Hence, we can conclude that they are logically equivalent.
Answer:
"You passed the test!"
Explanation:
Here user reading grade "test_score" and checking the student score in "If" condition. If it is less than 60 we are printing "You failed the test!" and if it is >60 we are outputting the string "You passed the test!" and else if it not satisfying any of these then we are printing "You need to study for the next test!".As "test_score" value is 90 which is >60 it satisfies the condition >60. So we are printing the string "You passed the test!"
It is called the file extension or filename extension. It is a suffix that indicates the file format.