निम्नलिखित वाक्य के किस भाग में व्याकरणिक त्रुटि है? 'He knew (a) / that his partner (b) / will not be able (c) / to solve the problem (d)'

Identify the part of the sentence that contains a grammatical error: 'Had I knew the answer, I would have raised my hand.'

Identify the part of the sentence that contains an error: A bigger budget has been set aside for this years marketing campaign in Asia.