请问这是那个知识点，怎么理解

问题如下：

The new Heydon Quant Fund will use a factor-based strategy. Nowacki assembles a large dataset with monthly standardized scores and monthly returns for the strategy to back-test a new investment strategy and calculates the information coefficient. FS(t) is the factor score for the current month, and FS(t + 1) is the score for the next month. SR(t) is the strategy’s holding period return for the current month, and SR(t+1) is the strategy’s holding period return for the next month.

In Nowacki’s back-testing of the factor-based strategy for the new fund, the calculated information coefficient should be based on:

选项：

A.

FS(t) and SR(t)

B.

FS(t) and SR(t + 1)

C.

SR(t) and FS(t + 1)

解释：

The purpose of back-testing is to identify correlations between the current period’s factor scores, FS(t), and the next period’s holding period strategy returns, SR(t + 1).