The patient’s temperature was the same for two times during the period given. What were those two times?

A) $1p.m$ and $2p.m$
B) $2p.m$ and $3p.m$
C) $12noon$ and $3p.m$
D) $9a.m$ and $10a.m$

Hint: In this question, we are given a line graph which denotes the temperature of a patient at different hours of the day. We have been asked to tell those two hours when his/her temperature was the same. Look for that period of time which has been connected by a straight horizontal line and not by an increasing or decreasing line. That period will be your answer.

Complete step by step solution:
We are given a line graph which denotes the temperature of a patient at different hours of the day. We have been asked to tell those two hours when his/her temperature was the same. We will start by noting down the temperature of the patient at the given hours.
$ \Rightarrow $$9a.m$=$35.5^\circ C$
$ \Rightarrow 10a.m = 36^\circ C$
$ \Rightarrow 11a.m = 39^\circ C$
$ \Rightarrow 12noon = 38.5^\circ C$
$ \Rightarrow 1p.m = 36.5^\circ C$
$ \Rightarrow 2p.m = 36.5^\circ C$
$ \Rightarrow 3p.m = 37^\circ C$
Now, as we can see that the temperature of the patient was the same at $1p.m$ and $2p.m$.

Option A is the correct answer.

Note: In the given question, we could also have used a shortcut method, wherein we check the two such points which are connected by a straight horizontal line. The logic behind this is that if the points are marked at the same levels, then joining them will give a straight horizontal line and not a vertical line as it arises when two points which are at different levels are joined.
In this question, we can notice that $1p.m$ and $2p.m$ are connected by a straight line and others are connected by vertical lines.