Answer: conducts electricity and heat efficiently, resists melting at high temperatures.
Explanation: Ionic compounds are formed by transference of electrons and leads to generation of cations and anions which are held by strong coloumbic forces. eg: NaCl
Ionic compounds when dissolved in water dissociates into ions and thus are good conductors of heat and electricity.
They are conductors not insulators.
They have very high melting points as they are held by strong coloumbic forces.
They dissociate into ions when dissolved in water.

Answer:
A. modern organisms closely resembling fossils
Explanation:
Fossils are defined as the preserved remains or traces of living organisms from past.
Fossils are considered as an evidence for evolution because they represent the existence of life on earth and shows the difference between the life in past that life on earth today. With the help of fossil, it is easy to determine the age of fossils which further help to determine that how modern organisms have evolved from the past.
Hence, the correct answer is "A. modern organisms closely resembling fossils".