It's B, I'm doing my online school assignment and this was the correct answer.
Complete Question
The complete question is shown on the first uploaded image
Answer:
a
No singular point due to the exponent in the solution
The interval is 
b
NONE
Step-by-step explanation:
From the question we are told that

The generally solution is mathematically represented as

=> 
integrating both sides

=> 
=> 
=> 
Here 
=> 
From the above equation we see that the domain for x has no singular point the interval is

Also there is no transient term in the general solution obtained because as
there no case where 
5^2 + 12^2 = c^2
25 + 144 = c^2
169 = c^2
take the square root of both sides
+ - 13 = c
Answer:
This depends on the situation. For context, you use less than when your inequality CANNOT exceed more than.
You would use less than or equal to if your inequality can be equal to a number. Here's an example.
John needs to buy X oranges and Y apples. He can AT MOST buy 10 total fruits.
x + y (equal to or less than) 45
John needs to buy X oranges and Y apples. He CANNOT buy more than 10 total fruits.
x + y < 45