Based on the financial data provided in the materials, use Zhen Hua Company as the comparable entity. Evaluate the value (per share) of Sobright Company using the three different valuation-models: Price-to-earnings ratio (P/E) model; price-to-book ratio (P/B) model; and price-to-sales ratio (P/S) model, respectively. Besides, indicate the limitations of using P/B Model.

2010年上海世博会期间，国内外游客将有几千万，这需要许多志愿者参与到世博会的服务中来。下列对志愿者的付出与回报说法正确的是   [ ]

①每一种责任都往往伴随着代价与回报 

②承担责任付出的代价越大，得到的回报就越多

③很多代价与回报往往不能用金钱来衡量

④他们承担责任所获得的回报更多的是无形财富

A．①②③   

B．②③④

C．①②④   

D．①③④