The rose is---as a symbol of love in many countries.

consider 指经过深思熟虑或由亲身经历而认为；regard 指用眼睛看,这种判断通常是指表面上的观察!玫瑰被视为爱情的象征可以说是经过深思熟虑才确定的,因此选consider ! be considered as和 be regarded as 意思差不多,都指被认为,被看作!