In the following question, several spellings of the same word are given. Select the correctly spelt word that refers to a person who places another in a hypnotic state.

Introduction / Context:
This question tests spelling of a common, though slightly technical, English word related to psychology and therapy. Correct spelling is important in exams, formal writing, and professional communication because wrong letters can change the appearance of a word enough to confuse readers or suggest weak language skills. Here, the word refers to a person who uses hypnosis, so we must recall both the root word and the standard way English forms agent nouns from it.

Given Data / Assumptions:
The stem tells us that all options are possible spellings of the same intended word.

The target word is someone who performs hypnosis.
The familiar root in English is hypno, as in hypnosis and hypnotic.
Agent nouns are often formed with the ending ist, as in dentist or pianist.
We assume British spelling, which still uses the same form for this word.

Concept / Approach:
The correct spelling comes from the root hypo plus not plus ist, combining to form hypnotist. The cluster hypn is fixed and the vowel o appears before the t. English does not usually replace i with y in this word, and the consonant sequence should remain stable. The simplest way to solve the question is to quickly write the word from memory, then compare it with each option and see which one matches exactly. We also verify that the vowels and consonants appear in the right order without extra or missing letters.

Step-by-Step Solution:

Verification / Alternative check:
We can verify by thinking of related words. Hypnotic is spelled h y p n o t i c and hypnosis is spelled h y p n o s i s, so the cluster hypno is stable. The word hypnotist simply attaches ist to this family of words. Dictionaries and textbooks on psychology use the spelling hypnotist, and any other arrangement, such as hipnotist or hypnotyst, would be flagged as incorrect. Reading the options aloud also helps, because the correct spelling feels familiar from common usage in media and books.

Why Other Options Are Wrong:
The option hypnotyst incorrectly uses y instead of i in the ending and does not match standard English patterns for this word. Hipnotyst and hipnotist drop the second h and use hipno instead of hypno, which is not the accepted spelling. Hypnotis omits the final t and does not show the full ist ending used to form agent nouns. Although these variations may sound similar when pronounced, they are orthographically wrong and would be considered spelling mistakes in exams and formal writing.

Common Pitfalls:
Learners often confuse i and y in English spellings or try to simplify clusters by dropping letters, especially in less common words. It is important to remember that the hypno family keeps the h y p n o pattern without simplification. Another pitfall is assuming that if a word sounds correct, any approximate spelling is acceptable. In exam contexts, only the exact dictionary spelling earns full marks. Therefore, memorising the correct forms of technical words like hypnotist is useful for both scoring well and writing accurately.

Final Answer:
The correctly spelt word is hypnotist.