Ddt, dde, pcbs and pbdes are all
ddt, dde, pcbs and pbdes are all
a
biodegradable and do not persist in the environment
b
toxic at the organism level but not at the ecosystem level
c
teratogens
non-biodegradable and subject to bioaccumulation and/or bioamplification
d
approved for use as pesticides by the epa

The answer is C teratogens non-biodegradable and subject to bioaccumulation and/or bioamplification 

DDT () is persistent, non-degradable insecticide and organic pollutant readily accumulated to soils and consequently affects organisms.
DDE () is non-degradable pesticide toxic to birds at the first place.
PCBs (polychlorinated biphenyls) are non-degradable organic compounds  very toxic to the environment.
PBDEs (polybrominated diphenyl ethers) are non-degradable compounds very toxic to the environment, even able to affect brains of animals in the development period.

b. read the phase at the intersection of any given temperature and pressure.

a. suckling by young

b. hypothalamus

c. dopamine

d. trh

e. anterior pituitary

f. mammary glands

g. milk production