In reference to the current hostility toward smoking, smokers frequently expressed anxiety that their prospects for being hired and promoted are being stunted by their habit.
(A) In reference to the current hostility toward smoking, smokers frequently expressed anxiety that
(B) Referring to the current hostility toward smoking, smokers frequently expressed anxiety about
(C) When referring to the current hostility toward smoking, smokers frequently express anxiety about
(D) With reference to the current hostility toward smoking, smokers frequently expressed anxiety about
(E) Referring to the current hostility toward smoking, smokers frequently express anxiety that

oa e

please explain expressed vs express
and when referring to vs referring to
anxiety that vs anxiety about