The correct option is A 3-ethyl-4,4-dimethylheptane
3-ethyl-4,4-dimethylheptane
Let's follow standard procedure.
First identify the longest chain. If you do so, you will see that we have a 7-carbon chain. So, hept
Then you can see that there are 2 methyl groups and 1 ethyl group as the substituents.
Once you find the substituents we need to assign numbers.
What do you think? 3-ethyl-4,4-dimethylheptane is fine right?
Remember the lowest locant rule.