Exam PL-400 topic 5 question 19 discussion

You are creating a canvas app for a bank. Consumers will enter information into the app when they apply for a loan.
The input form for the app must display fields to prompt the consumer for their first name, last name, address, and the requested loan amount.
Immediately after a consumer enters a value for the LoanAmount field, the background color for the column must change. The background color for the column must change to red if a consumer enters a value of more than $5,000 and must turn green for values less than or equal to $5,000.
You need to implement the required behavior.
Which option should you use?