In reflex pathways: a) the receptor is a membrane protein b) the efferent is always a motor neuron or hormone c) the efferent is the cell or tissue that does the final work in the pathway d) the integrating center for a neural or neuroendocrine reflex is always some part of the CNS

D

Explanation:

The neural pathway regulates the action reflex. At times sensory neurons synapse occur in the spinal cord rather than the brain, this allows for a quicker reflex action. Synapses in the spinal cord activate spinal motor neurons without delay, which is likely the case if the signals go to the brain, the brain doe however receive the sensory input during the reflex action.

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.