One reader made the claim, 'The Big Dig was a more amazing engineering feat than the Chunnel because it required engineers to dig through dirt that collapsed easily." Which of these counterarguments addresses this claim? A. The Chunnel connected England and France under the English Channel.
B. The engineers on the Big Dig were able to solve this problem by using slurry walls.
C. The dirt in Boston had been put there on purpose by people as they built out the city.
D. The engineers on the Chunnel had to deal with both digging through solid rock and digging under water.​