I was confused about this question when I tried it. I understood part A, where I found the oxidation number for manganese in permanganate was 7+. I also understood part B, where I got the reducing agent to be Fe. But I was confused about the color change at the end and how that relates to titration (part C).

5 Fe2+(aq) + MnO4- (aq) + 8 H+ (aq) → 5 Fe3+(aq) + Mn2+(aq) + 4 H2O(l)

The mass percent of iron in a soluble iron (II) compound is measured using a titration based on
the balanced equation above.
(a) What is the oxidation number of manganese in the permanganate ion, MnO4-
(aq)? (1 point)

(b) Identify the reducing agent in the reaction represented above. (1 point)
The mass of a sample of the iron (II) compound is carefully measured before the sample is
dissolved in distilled water. The resulting solution is acidified with H2SO4(aq). The solution is
then titrated with MnO4- (aq) until the end point is reached.

(c) Describe the color change that occurs in the flask when the end point of the titration has been
reached. Explain why the color of the solution changes at the end point. (2 points)

The color change comes from the excess permanganate. During the time iron-II is present the redox reaction takes place, permanganate loose its colour. But if all iron is consumed the next drop permanganate  will change the colour to pink violet in the flask.

Quote(a) What is the oxidation number of manganese in the permanganate ion, MnO4-
(aq)? (1 point)

MnO4-
Here you can assume Mn as x and each oxygen is -2
so X + 4(-2)= -1
X= -1+8= +7
so +7

Quote(b) 5 Fe²⁺(aq) + MnO₄^- (aq) + 8H⁺ (aq) →5Fe³⁺(aq)+Mn²⁺(aq) +4H₂O(l)
Identify the reducing agent in the reaction represented above. (1 point)

Check the change in oxidation number and the species which is undergoing oxidation is the reducing agent because it is helping in the reduction of other species by giving electrons.
MnO₄^- ---> Mn ²⁺ is gain of 5 electrons  reduction
Fe²⁺ ---> Fe³⁺ is the loss of one electron (oxidation)
So reducing agent is Fe²⁺

Quote(c) Describe the color change that occurs in the flask when the end point of the titration has been
reached. Explain why the color of the solution changes at the end point. (2 points)

MnO₄^- is pink in color and Mn₂⁺ is colorless.
At the end point when no more ferrous ions are left in solution then permanganate ion stop undergoing reduction and imparts pink color to the solution.