UPSC Civil Services 2018 Prelims General Studies Paper I

Sand Mining wrecks the intertidal area and creates the imminent danger of saline water ingress into fresh water." Meaning salinity will increase, so statement #1 is wrong, by elimination we've answer "B" 2 and 3 only.
In this question, first statement is wrong, and you've to identify right statements. So in real exam stress, some students may have made error of reading / ticking, and they'd have ticked the wrong option A: only 1. (you're right that it's wrong statement, but you're not asked to tick the wrong one.) So, be mindful of ticking in OMR.