Change of heart

[TuAnh]

Test No. incompl/inter-1 "Applying for that Job", question 5

The government has changed its policy and had a complete change of ..........

(a) view
(b) opinion
(c) mind
(d) heart

Test No. incompl/inter-1 "Applying for that Job", answer 5

The government has changed its policy and had a complete change of heart.

Correct answer: (d) heart
_________________________

Please explain for me the reason that "mind" can't be used in this sentence.
Thank.

[Torsten]

If someone has a change of heart, they change their opinion or the way they feel about something. You can also change your point of view.
So, change of heart is a fixed expression.
However, you can change your mind about something. (here, change is a verb)

TOEFL listening lectures: Which country was not an important cotton grower in the 19th century?

[Tuanh]