2.单选题(2分)-|||-设 backsim N(1,4), ϕ(x) 为标准正态分布的分布函数,则-|||-P lt xlt 2 __-|||-A https:/img.cdnjtzy.com/zyb_c234d9988cb6ef6dd3ea9c85d3d93e43.jpg-(1)(0.5)-|||-B (p(0.5)+(p(-0.5)-|||-C (p(0.5)-1-|||-D (p(-0.5)-1