well , it's true because they are of sp3d type occur on sets of four
the correct answer is choice D
Answer:
Condenser
Explanation:
A condenser is laboratory apparatus used to condense vapors — that is, turn them into liquids — by cooling them down. Condensers are routinely used in laboratory operations such as distillation, reflux, and extraction(Wikipedia).
Condensers of of practical importance especially in synthetic organic chemistry and in separation science where vapours are often condensed and collected the substance is collected in pure form by distillation.
Answer : Option B) Plant stomata opening and closing to maintain homeostasis.
Explanation : Claude Bernand was a French Physiologist who first discovered about "homeostasis" which is defined as the controlled stability of the internal milieu, or internal environment, of cells and tissues in plants.
In plants stomatal opening and closing was done for maintaining homeostasis with the external and internal plant environment.