Sacrifice of Form and number of body checks

[Darksatin]

Hello,
A company is facing Scorba at Home (3 strikes at 13/8).
I play Sacrifice of Form on my Wizard.
All the strikes of the attack fail.
So, I must make body checks (at + 3) to determine if the attack is defeated. But how many body checks ?

A : 3 body checks Vs 8
B : 1 body check Vs 10
C : 1 body check Vs 8

[Konrad Klar]

Sacrifice of Form may be played only after strikes are assigned.
So a number of body checks is equal to a number of assigned strikes. To defeat Scorba at Home a result of each dice roll +3 must be greater than 8.