Wrich statement regarding market efticlency is true?

a$.$ Weak$-$form market efficiency implies that recent trends in stock prices are of no use in predicting future stock prices.

b$.$ Market efficiency implies that all stocks should have the same expected return.

c$.$ Semistrong$-$form market efficiency implies that as soon as any public or private information comes into being it is incorporated into stock prices.

d$.$ According to strong$-$form market efficiency, insiders would find it possible to consistently earn abnormal returns in the stock market even if they have superior knowledge about the

same