What is the meaning of consequence as it is used in the dialogue

In which two sentences does the author use an ironic tone toward the subject

The voussoirs rest on the centering until the keystone is wedged into place. at that point, the centering can be dismantled. what does the word dismantled mean? a. to take apart b. to put together c. to cover d. to lift up

What aspects of a story the reader understand the authors purpose