The origins of the alphabet are unknown, but there are several theories as to how it developed. One popular proposal the Proto-Sinaitic theory is that the history of the alphabet began in Ancient Egypt, more than a millennium into the history of writing. Under this theory, the alphabet was invented to represent the language of Semitic workers in Egypt (see Middle Bronze Age alphabets), and was at least influenced by the alphabetic principles of the Egyptian hieratic script. If correct, nearly all alphabets in the world today either descend directly from this development or were inspired by its design.

Oh no, don't blame me sir

The English word alphabet came into Middle English from the Late Latin word alphabetum, which in turn originated in the Greek (alphabtos), from alpha and beta, the first two letters of the Greek alphabet.[4] Alpha and beta in turn came from the first two letters of the Phoenician alphabet, and originally meant ox and house respectively

so the answer is The Greek

When human beings wanted to pass information to others without sound or action the symbols ( letters )were created. the group of the symbols represent alphabets. all ancient human beings are the reason for it . we cannot single out them.

Humans

The word alphabet comes from old greek and refers to the first two letters "alpha" "beta" although the second was probably pronounced as a "V".
The Sumerians had the first recorded writings known as "Cuneiform" because of it's wedge shaped symbols some 3000 years B.C. so it's likely that they had the first alphabet.