No, grandparents is a common noun, therefore you don't capitalize it. It would be different if you had the names of the grandparents. Like if your grandma is named Martha. You would have to capitalize their name since it is a proper noun
Answer:
A star can live for billions of years: Option A.
Explanation:
The given excerpt clearly indicates that a star can run out of hydrogen and energy only after millions or billions of years. Only then it collapses to a little ball with gravity. This means it would live till those millions or billions of years.
'Black hole' is a region in the space which has such strong gravitational force that it pulls every object that passes through it. Albert Einstein predicted that black star would exist if a dead star also had enough gravity. Hence, "option A" is the correct one.
Maybe that guys will come into your house, (or life) and can either can grow with you and help you, or destroy you (hence the hammer).