The word that is NOT an action verb from the options given is 'happy.' Unlike the others, 'happy' describes a state of being rather than an action. This makes it the correct answer to the question. ;
The word that is NOT an action verb from the options given is 'happy,' which describes a state of being rather than an action. The other options—trained, tested, and designed—are all action verbs. Thus, the correct answer is option d, happy.
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