<span>The </span>PRESENT PROGRESSIVE TENSE<span> indicates continuing action, something going on
now. This </span>tense<span> is
formed with the helping "to be" verb, in the </span>present tense, plus the present<span> participle
of the verb (with an -ing ending): "I am buying all my family's Christmas
gifts early this year.</span>
The correct answer between all
the choices given is the first choice or letter A. I am hoping that this answer
has satisfied your query and it will be able to help you in your endeavor, and
if you would like, feel free to ask another question.
'They are climbing to the top of the Aztec temple' is an example of progressive verb. Which means the action that is currently and still hapening the main characteristic of a present progressive s the appearance of (is/am/Are) + Verb-Ing