1 .
Consider a square with sides of length 3. Assume this square contains 10 points. Which of the
following is true?
(a)
At least two of these $n$ points are at distance at most $\left. 1 \middle/ \sqrt{2} \right.$.
(b)
None of the above.
(c)
At least two of these $n$ points are at distance at most $\sqrt{2}$.
(d)
At least two of these $n$ points are at distance at most $1$.