How should I answer this question about measuring airspeed using dynamic pressure?
You're confused! Great! Confusion is just an opportunity to learn.

In the spirit of education, I won't answer your question, but I will give you some things to consider.


"Give your argument on the statement" - This usually means you're being asked to support or refute whatever comes next. It will be up to you to decide which is appropriate.
Measuring dynamic pressure - What is dynamic pressure? Are there other kinds of pressure? Is there something else besides pressure that could be measured instead?
is - Is it or is it not?
the way to - the only way? Are there other ways? 
determine the indicated airspeed - Is that what is determined? Is anything else determined? Is indicated airspeed the proper thing to determine or do you need something else?
of an aircraft. - Is that correct? 


If you can answer all of those, you should have no problem putting them together into a solution. If you're having problems with a specific portion, let us know what's unclear.