WeWeWeb Bridge

Answers
♥7 Most players would select to play ♣A or ♣K as it is a standard lead. However, in the case, it allows declarer to cross ruff the black suits and end play East. For your hand, you have strength in all the side suits, declarer cannot develop a suit easy. Cross ruff seems the only way to make the contract. Also, your partner's double shows that he has one or two high cards in the trump plus some points in the side suits. Don't help them to develop the side suits, lead the trump to reduce their chance to corss ruff.
Statistics
♣A (62%)    ♥7 (16%)    ♣K (4%)    ♦2 (4%)    ♦J (4%)    ♦Q (4%)    ♠4 (4%)