Brain size has increased nearly 3x in 4 million years.
<h2>Answer:</h2>
The correct answer is the option C.
Which is we add equal amount of salt in all the water samples.
<h3>Explanation:</h3>
- As in experiment we have to indicate that the boiling point of water increases with the addition of salt.
- Now we also know that water contains many salts as compared to the distilled water.
- So the boiling points of simple water and distilled water would be bit different.
- So we cannot choose one for our experiment. Instead we use all water samples of equal volume adding equal amount of salt in all samples.
- Then we will compare results for a net answer/result of experiment.
I am sorry I wish I could help you. Sorry
I would have to say it was in the 1860s