I have a column of geometry values (point values) and I have another distinct geometry value (polygon). I want to find out which point values from my column is inside the polygon (distinct geometry value). I have used st_contains, but it is giving error as more than one row returned by a subquery. How to do it?

I have a set of geometry values (point values). I have another distinct geometry value (polygon). I want to find out which points are inside (contains) the polygon. Say, my polygon is B. And the set of points are: {A1, A2, A3...}. I want to check whether B contains A1 then A2 then A3 and so on. I can do it individually by ST_Contains. Such as:

select * from table1 where st_contains(B,A1)

But I don't want to check individually. I want to check for the whole set at a time, i.e {A1, A2, A3...} and want to find out the points (i.e A3 and/or A2) which are contained in B means which has given true value for ST_Contains. How to do it?