Step-by-step explanation
Just to come to your house, you have to pay him $95. Then,

After he arrives, time passes and you have to pay him $35 per hour. If he works in your house for t hours, you must pay him

Then, "something" is 35*t.
Answer
The linear function encoding the cost C for an electrician to come to your house and work for t hours is

The answer is C.