The correct choice is (c) Nomographs
To explain: A nomogram (from Greek νόμος nomos, “law” and γραμμή grammē, “line”), also called a nomograph, alignment chart or abaque, is a graphical calculating device, a two-dimensional diagram designed to allow the approximate graphical computation of a mathematical function. An arrangement of two linear or logarithmic scales such that an intersecting straight line enables an intermediate values or values on a third scale to be read off.