If Earth's accretion had been slow and low heat what would be the deepest effect on early differentiation?

Correct answer: Density based separation would be less effective

The governing concept is planetary differentiation, in which materials of different densities separated under gravity while the young Earth was sufficiently hot and partly molten. Heat from accretion and other early processes helped materials move; dense metallic substances could sink toward the centre, while lighter silicate materials remained nearer the outer parts. If accretion had been slow and generated little heat, melting and internal mobility would have been reduced. Density-based separation would consequently have been less effective, making a clearly layered interior less likely or slower to develop. Thus option A is correct. Ozone formation, ocean drying, and photosynthesis do not describe the direct physical effect of reduced accretional heat.