To type mathematical formulae and chemical equations ------- is usedADetent releaseBMargin releaseCVariable line spacerDNoneAnswer: C. Variable line spacer Read Explanation: This is used to get any fraction of space between lines.To type mathematical formulae and chemical equations Variable line spacer is used This is also useful to type on ruled sheets, to type chemical formulae, to do re-insertion work and to type combination characters. Read more in App