Answer : The correct option is, (d) micro-
Explanation :
Metric system : The Metric System measured the things in meters, grams, liters, etc and adds prefixes like kilo, milli and centi to the count orders of the magnitude.
In metric system, a metric prefix is a unit prefix that comes before the basic unit of measure to indicate the fraction of the unit.
Metric system (factor) Prefix Symbol
1000 kilo- k
100 hecto- h
10 deca- da
0.1 deci- d
0.001 centi- c
0.0001 milli- m
0.0000001 micro- μ
Hence, according to the metric system prefix the prefix used for 0.000001 is, micro-
