Which of the following describes a response to external stimuli ?
a. a boy sneezes when exposed to a cat dander.
b. a girl eats food when she is hungry.
c. a child becomes hyperactive do to a chemical imbalance.
d. a person yawns when oxygen levels in the blood are low.

Saliva, sweat, pee, and dander (dead skin cells) can all trigger allergies. Pet fur also traps mold, pollen, and other outdoor allergens that make you sneeze and your eyes water.

Explanation:

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'