![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
Which of the following answers will lead to an explosion soon?
A.
Small explosions happening around the volcano for several weeks.
B.
The bursting out of cracks from the craters at the bottom of the volcano.
C.
The dome in the volcano begins to expand.
D.
Melting process of rocks and gas at the top of the volcano.