Task: Question Answering
Input (English): Question: Which of the following multivariate analysis techniques analyzes the covariation presented by a set of metric variables, susceptible of being synthesized in a set of common factors that lie behind them? 
 Options:  <1> Multiple discriminant analysis. <2> Multiple linear regression <3> Multivariate analysis of variance. <4> Factorial analysis. <5> Analysis of structural equations.
Output (English): 4