Answer:
The correct answer will be- 100 billion brain cells or neurons
Explanation:
The development of brain starts after three weeks of conception in the womb and the brain cells called neurons starts developing in the brain.
The brain usually develops about 100 billion neurons at the time of birth with very few synapses about 2500 synapse per neuron. In the first few years, the number of neurons increases to trillions and the formation of synapses begins and reaches about 15000 synapses per neuron at the age of five.
Thus, 100 billion brain cells or neurons is the correct answer.