Any member of a small class of words found in many languages that are used as replacements or substitutes for nouns and noun phrases, and that have very general reference, as I, you, he, this, who, what. Pronouns are sometimes formally distinguished from nouns, as in English by the existence of special objective forms, as him for he or me for I, and by nonoccurrence with an article or adjective.
Bro I know it's long
The answer is b
The pequeña yo había soñado con delfines muchas veces
1. Work out the Mean (the simple average of the numbers)
2. Then for each number: subtract the Mean and square the result.
3. Then work out the mean of those squared differences.
4. Take the square root of that and we are done!