D .............. im pretty sure its this one :)
There could be many answers to this question, but a possible one is embryo!!
The answer is: Santorio’s thermometer required mercury to work properly. Because both of them are portable not just the one is. And, also, A thermometer does not measure in Kelvin. If this helps, thank me. If this really helps, thank me and, crown me brainiest answer. Also, rate, and comment. This helps me to improve answering, and helps you to get a better answer.
Hardness Smartest suggestion
Answer:
cell, tissue,organ, organ system, organism
