I realised they wanted to be alone together, so I felt very awkward.

The correct answer is C. embarrassed.

To feel awkward is to

feel uncomfortable or embarrassed in a social situation. It is often caused by feeling out of place or like you don’t belong. In the given situation, the speaker feels awkward because they realize that the two people they are with want to be alone together. This can make the speaker feel like they are intruding or like they are not wanted.

The other options are not as accurate descriptions of the speaker’s feelings. Cumbersome means difficult to handle or control. Unwieldy means difficult to use or manage. Clumsy means awkward or uncoordinated.

Here are some examples of how the word “awkward” can be used in a sentence:

• I felt awkward at the party because I didn’t know anyone.
• The job interview was awkward because I didn’t have any experience.
• The conversation was awkward because we didn’t have anything in common.