In the 1820’s, anthracite coalfields opened

[ayushrastogi82]

[Deleted because this question is from a banned source - see below.]

Source: verbal set 8

In E, 'as' is used as conjunction or prepostion? According to me, 'as' is used as 'when'
e.g. As a child, I was very naughty.

This means it is used as a prepostion but then how come it is introducing a clause instead of a phrase?

[esledge]

Please read (and follow!) the forum guidelines before posting.

"GMAT Sets" is a banned source, as it uses copyrighted material from GMAC without permission.