[" A student measured the length of a rod and wrote it as "],[3.50cm" .Which instrument did he use to measure it "],[" (a) A meter scale "],[" (b) A vernier calliper where the "10" divisions in vernier scale "],[" (b) A vernier calliper where the "10" divisions in vernier scale "],[" matches with "9" division in main scale and main scale "],[" (c) A screw gauge having "100" divisions in the circular scale "],[" and pitch as "1mm],[" (d) A screw gauge having "50" divisions in the circular scale "],[" and pitch as "1mm]