The following pie charts represent the distribution of candidates who were enrolled for an exam and the candidates (out of those enrolled) who passed the exam in different institutes:



The difference between the total number of candidates who passed from institutes $S$ and $P$ combined and the total number of candidates enrolled from institutes $T$ and $R$ combined is:

1. A
   $400$
2. B
   $440$
3. C
   $300$
4. D
   $399$