Reading Mis-adventures

While researching for techniques on how to teach reading to children, I discovered www.starfall.com, a site that offers lots of games that help teach reading skills.

At lunchtime today, Pia came to visit the office.  I showed her one of the screens.  On the screen is a drawing of a tin can, and the incomplete word _AN.  The child is supposed to pick the correct letter from a group of four letters, to complete the correct word 'CAN'.

The selection of four letters are: F, P, C, and R.

I asked Pia, which letter is the correct one?

Pia: (Confidently, and pointing generically to the screen) 'B' !