Which of the following were major contributing factors to the $2008$ financial crisis?

$1.$ Deteriorating mortgage underwriting standards

Il$.$ Increasing number of mortgages sold to Fannie and Freddie IlI. Bond raters under estimating the risk of MBS

$$ A$.$ I and I only

$$ B$.$ I, Il and III

$$ C$.$ I and Ill only

O D$.$ Il and Ill only