Hello!

Let's start with the difference between raise and rise:

Raise: We use the verb "to raise" when talking about a person performing an action onto another person or thing. We can raise the temperature in our room by lighting a fire, raise a book over our head, or raise money for a charity.

Rise: We use the verb "to rise" when talking about an action a person or thing does to itself. We rise out of bed in the morning, the temperature rises during the summer months, and the stock market rises on good days. No one is doing these actions on their behalf - we, the temperature, and the stock market are acting alone.

Now that we know this, we can rule out answers A, B, and E. All of them use some form of "to raise," suggesting the sea level is being raised by some other force. It's not. The sea level rises on its own. No one is pushing a button to make it happen.

This leaves us with options C and D. Now we have to deal with singular/plural agreement.

D is incorrect because the phrase "its present height" is a singular phrase referring to "the seas," which is plural. "Its" and "seas" don't match up, so it's wrong. To fix it, you would have to change "its present height" to "their present heights."

C is our final option, and it's the correct one because the singular "its" is now referring to "sea level," which is also singular and matches up perfectly!

I hope this helps. I'm available if you'd like any follow up.