Explain how water erosion by groundwater can form a cave

The sun's parallax would be 180 degrees, greater than which you can't get.  so a. would be your anwser 

Answer(12) judaism; ans(11) all of the above; //ans(10) islands that are artificially created; //ans(9) people accept that the caste system keeps order in society and prevent chaos; ///ans(8),brahman; ans(7) the sikhns; ///ans(6); the non-cooperation movement; asn(5)sporadically grant congressional requests; /ans(4) all of the above; ///ans(3) true; //ans(2) true; //ans(1) false;