'came to be apart' vs. 'came apart'

[Sergue]

English Grammar Tests, Elementary Level

ESL/EFL Test #87 "Common English Errors (3)", question 6

As soon as I picked up the rare object, it ..........

(a) was not together
(b) came to be apart
(c) came apart
(d) was separated

English Grammar Tests, Elementary Level

ESL/EFL Test #87 "Common English Errors (3)", answer 6

As soon as I picked up the rare object, it came apart.

Correct answer: (c) came apart

Your answer was: incorrect
As soon as I picked up the rare object, it came to be apart.
_________________________

Dear sir,
Would you mind to explain this sentence for me
Why use "came apart"

Sergue

[Conchita]

In the sentence:

"As soon as I picked up the rare object, it came apart"

the phrasal verb came apart is used to indicate that the object broke, came to pieces or separated into pieces.