The correct condition among the following with reference to sexual reproduction in Rhizopus stolonifer is

Question

$\begin {array} {1 1} (1)\;'+'\: \times \: '-' \: = \: zygospore & \quad (2)\;'+'\: \times \: '-' \: = \: No\: zygospore \\ (3)\;'-'\: \times \: '-' \: = \: zygospore & \quad (4)\;'+'\: \times \: '+' \: = \: zygospore \end {array}$