Statistics: What statistical tool can I use to find the significance of my hypothesis?

I have survey results where 700 people choose A, 650 people choose B, 100 people choose C and 200 people choose D. My hypothesis is that a majority of people will choose A.

What can I use to find out how likely my hypothesis is true if we assume each choice is equally likely to be picked?

If there is more information I need, please let me know what I need.

Thanks in advance