In this spelling question, four similar looking words are given. Choose the correctly spelt word for the verb that means "to move in waves or with a wavy motion".

Introduction / Context:
This is a spelling based question from English vocabulary. You are asked to identify the correctly spelt word among four options that all look similar. The intended word is the verb meaning "to move in waves or with a wavy motion", which is commonly used in descriptions of water, flags, grass or even sound waves. Spelling questions test your visual memory of correct English forms, which is especially important for writing and formal exams.

Given Data / Assumptions:

• Four options are given, all variants of a similar sounding word.
• The correct verb should mean "to move or cause to move with a smooth, wavelike motion".
• Only one option matches the standard dictionary spelling.
• No additional context sentence is provided, so recognition must come from prior knowledge.

Concept / Approach:
The word you are looking for is "undulate". It comes from the Latin root "unda", meaning "wave". In English, "undulate" is spelled with "un" followed by "dulate". Knowing roots and common English spelling patterns helps you quickly reject incorrect variants that add or remove letters randomly. In spelling questions, the strategy is to recall how you have seen the word in books, articles or dictionaries and compare that internal image with the options offered.

Step-by-Step Solution:
Step 1: Identify the target meaning: the word used to describe something moving in smooth waves is "undulate".Step 2: Visualise the correct spelling: U N D U L A T E.Step 3: Examine option B "undulate" and see that it matches exactly: un + dul + ate, with the letters in the right order.Step 4: Check option A "andulate" and notice that it starts with "an" instead of "un", which is incorrect.Step 5: Examine options C "undulete" and D "andulete" and see extra letters and misplaced vowels that do not match the standard form.

Verification / Alternative check:
A quick verification method is to put the candidate spelling into a sample sentence: "Tall grasses undulate in the wind." If you have read similar lines in literature or nature descriptions, the spelling "undulate" should feel familiar. If you attempt "andulate" or "undulete", the word looks strange and unfamiliar, which is a strong sign that the spelling is wrong. Also, checking a dictionary in real practice will always confirm that the standard spelling is "undulate".

Why Other Options Are Wrong:
Option A, "andulate", incorrectly replaces the first syllable "un" with "an". There is no common English verb "andulate". Option C, "undulete", adds an extra "e" and mixes up the internal vowel sounds, creating a nonstandard form. Option D, "andulete", combines both errors, changing the first syllable and adding unnecessary letters. None of these incorrect variants appear in standard English usage.

Common Pitfalls:
Students sometimes choose misspellings that look fancy or complex, assuming that the longest or most unusual option must be correct. This is not a reliable strategy. Another pitfall is relying only on pronunciation; since several of the options may sound similar when spoken, you must rely on visual familiarity. To improve spelling skills, it helps to read widely and pay attention to how words look on the page, especially in high quality printed material.

Final Answer:
The correctly spelt word is undulate, which means to move with a smooth, wave like motion.