Is it possible to have a single force?

Yes it is possible to have a single force, this is possible, check the example below :

Example 1. I'am pushing pushing the table closer to the wall.

If you have just finished reading the example above , you should now know that there is only one force that is active at the moment. The table doesn't have an active force because it cannot fight against mine. The only type of "defense" the table has is friction because of the rubbing against the floor.

I hope this helped you a lot,

Ithink your answer is d