दी गई अक्षर श्रृंखला में प्रश्नवाचक चिह्न (?) को निम्नलिखित में से कौन सा पद प्रतिस्थापित करेगा? CRHT, GQLS, KPPR, ?, SNXP

Which number will replace the question mark (?) in the following series? 83, 79, 71, 67, 59, 55, ?

Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete? HLE23, JJH21, LHK19, NFN17, ?