I was browsing white house junior website. This is "problem 1" from
http://www.jeugdbrid...HJbulletin.html
West leads ♦J. We need to break the comminications of opponents to prevent diamond ruffs. How do you play?
A ) Win with ♦K, play a club
B ) Win with ♦K, lead a spade to ♠Q, if wins, play ♠A and discard a ♦
line ( A ) fails if east has a ♣A or K and hearts are distributed exactly as west holding ♥ 843 and east holds ♥A .
line ( B ) fails if east has ♠K and east has at least one small ♥. (you lose ♠K , ♥A, ♣A, and at least one ♦ ruff)
It appears that line A is the percentage play, but solution says something like "didn't you play as in line B? then you're down 1"
am i missing something, is line B really better?? otherwise I fail to understand the meaning of the problem...

Help

north east south west
1♠ pass 2♥ pass
3♦ pass 4♥ pass
pass pass