Explanation:

This question requires us to identify the word with incorrect spelling (वर्तनी की दृष्टि से अशुद्ध) among the given Hindi terms. Correct spelling is crucial for clear communication and adherence to grammatical standards. Let's examine each option: **Option (A): उपलक्ष्य (Uplakshya)** This word means 'occasion', 'aim', or 'target'. The spelling 'उपलक्ष्य' is grammatically correct in Hindi. It is derived from 'उप' (near) + 'लक्ष्य' (aim). There are no common spelling errors associated with this word, and its form is standard. **Option (B): अंतरात्मा (Antaratma)** This word means 'inner self' or 'conscience'. The spelling 'अंतरात्मा' is perfectly correct. It is a compound word formed from 'अंतर्' (inner) + 'आत्मा' (soul). The 'र्' (r) of 'अंतर्' combines with 'आ' (a) of 'आत्मा' to form 'रा', which is a standard Sandhi rule. This word is correctly spelled. **Option (C): सायंकाल (Sayankal)** This word means 'evening' or 'dusk'. The spelling 'सायंकाल' is correct. It is formed from 'सायं' (evening) + 'काल' (time). The use of the Anuswar (dot above the letter) for 'म्' (m) sound before 'क' is standard. This word is spelled correctly. **Option (D): महात्म्य (Mahatmya)** This word is intended to mean 'greatness' or 'glory', derived from 'महात्मा' (Mahatma - great soul). However, the spelling 'महात्म्य' is incorrect. According to Hindi grammar and word formation rules, when the suffix '-य' (ya) is added to a word to form an abstract noun, it often causes a lengthening of the first vowel of the original word (if it's short) and/or other phonetic changes. For 'महात्मा', the correct abstract noun form signifying 'greatness' is 'माहात्म्य' (Māhātmyā). The initial 'म' (ma) becomes 'मा' (mā) with a long 'ā' sound. Other examples of this rule include 'सुंदर' (sundar, beautiful) becoming 'सौंदर्य' (saundarya, beauty), and 'वीर' (veer, brave) becoming 'वीर्य' (veerya, valor). The spelling 'महात्म्य' is a common error, often arising from a direct application of the suffix without the necessary vowel lengthening. The correct form is 'माहात्म्य'. **Conclusion:** Based on the detailed analysis of each option, 'महात्म्य' (D) is the only word that is misspelled. The correct spelling for 'greatness' derived from 'महात्मा' is 'माहात्म्य'. Therefore, option (D) is the correct answer.