Find out one word from the given words which is different from other three (A) Barometer, (B) Thermometer, (C) Diameter, (D) Lactometer

Find out one word from the given words which is different from other three (A) Barometer, (B) Thermometer, (C) Diameter, (D) Lactometer

Explanation

 Diameter – Because barometer, thermometer, and lactometer are all measuring instruments, whereas diameter is a geometric term.