请各位高手解析一道新GRE逻辑题Whichofthefollowingmostlogicallycompletestheargumentbelow?EachyeareveryemployeeofSAICorporationmustenrollinoneofthetwohealthinsuranceplansofferedbySAI.Oneplanrequiresasizablem

　　请各位高手解析一道新GRE逻辑题

　　Whichofthefollowingmostlogicallycompletestheargumentbelow?EachyeareveryemployeeofSAICorporationmustenrollinoneofthetwohealthinsuranceplansofferedbySAI.Oneplanrequiresasizablemonetarycontributionfromemployees;theotherplanispaidforentirelybySAI.ManySAIemployeesenrollintheplanrequiringemployeecontributions.Thisfactdoesnotshowthattheyfeelthatthisplan’sbenefitsaresuperiortothoseprovidedbytheplanrequiringnoemployeecontributionsince----.

　　(A)theplanthatrequiresanemployeecontributioncostsandenrolledemployeesignificantlylessperyearthandotypicalhealthinsuranceplansofferedbycorporationsotherthanSAI

　　(B)onlySAIemployeeswhohaveworkedforSAIforatleastfifteenyearsareeligibletoenrollintheplanpaidforentirelybySAI

　　(C)thetwohealthinsuranceplanscurrentlyofferedbySAIaresubstantiallythesameplansSAIhasofferedforthepasttenyears

　　(D)mostoftheSAIemployeesenrolledintheplanpaidforentirelybySAIareunder50yearsold

　　(E)bothplansofferedbySAIprovidebenefitsnotonlyforemployeesofSAIbutalsoforchildrenandspousesofenrolledemployees为何不选C选B?请赐教!

　　懂了懂了!原来我只纠结在最后一句而忽略了上下文!受益匪浅!