The answer is option A.
The Student identifies the test tube
that stops bubbling first contains the catalyst.
Because Catalyst is a substance which
increases the rate of reaction, and the reaction shows that when a product is
obtained bubbles formed.
<span>When the student added X, Y and Z to the
test tubes. The one which is a catalyst fastened the reaction.</span>
I would say C but I’m not too sure.
An example of a person is not a bad guy and I don’t want him going back