B.
It has become uninteresting because it has been overused.
Step-by-step explanation:
Cliches are those phrases that have been used so much that they have lost their meaning that they wanted to convey and are used mindlessly without any thought.
While 'crystal blue water' is a good phrase to convey that some body of water is beautiful and extremely clean the phrase has lost its significance enough to not matter at all and no one would be thinking about anything when they read it.