निम्नलिखित में से कौन सी संख्या दी गई श्रृंखला में प्रश्न चिह्न (?) को प्रतिस्थापित करेगी? 121, 169, 289, ?, 529, 841

The arrival of which commission in India triggered widespread protests, including mass hartals across the country in 1928?

Which of the following leaders was instrumental in initiating and leading India’s struggle for independence?