Which statement related to customer sentiment analysis (CSA) is true?

Select one alternative: In contrast with asking customers to fill in a survey, opinion-mining from social media does not suffer from the survivor bias. Ready-made online CSA tools work better than custom-trained ones when the product is new and very different from those already on the market. The state-of-the-art CSA approach is to have customers in focus groups discuss a word cloud visualizing the frequencies of product-relevant words. Machine-learning techniques can classify the valence of individual words but cannot account for their context to infer the overall sentiment of a product review