Quote:
Until recently, anthropologists generally agreed that higher primates originated about 30 million years ago in the Al Fayyum region of Egypt. However, a 40-million-year old fossilized fragment of a lower jawbone discovered in Burma (now called Myanmar) in 1978 was used to support the theory that the earliest higher primates originated in Burma. However, the claim is premature, for______
Which one or the following, if rue, is the most logical completion of the paragraph above?
(A) there are no more primate species in Burma than there are in Egypt
(B) several anthropologists, using different dating methods, independently confirmed the estimated age of the jawbone fragment
(C) higher primates cannot be identified solely by their lower jawbones
(D) several prominent anthropologists do not believe that higher primates could have originated in either Egypt or Burma
(E) other archaeological expeditions in Burma have unearthed higher-primate fossilized bone fragments that are clearly older than 40 million years
ARGUMENT
[prem] higher primates originated 30mln yrs ago in Egypt;
[x-prem] but, 40mln yrs old lower jawbone, assumed to be that of a higher primate, was discovered in Burma;
[con] this finding is premature… y? weaken the x-prem.
(A) irev;
(B) this strengthen the x-prem;
(D) irev;
(E) strengthens;
Ans (C): yes, this weakens, since lower jawbones could be that of any primate.