患者男，67岁，因头痛、头晕、乏力、心悸、四肢发麻、身体不适就诊。查体：面色深红，略发绀，口唇及黏膜紫红，下肢肿胀并发现有发绀，脾大，心、肺正常，其他未见异常。血常规检查红细胞7.20×10¹²/L，血红蛋白227g/L，白细胞计数18.2×10⁹/L，血小板623×10⁹/L。骨髓穿刺：干抽现象，深红色。

此患者可能的诊断是（）

A.慢性粒细胞白血病

B.骨髓纤维化

C.真性红细胞增多症

D.继发性红细胞增多症

E.原发性血小板增多症

F.骨髓增生异常综合征

What is the WBS typically used for

A) To organize and define the total scope of the project.
B) To identify the logical person to be project sponsor.
C) To define the level of reporting the seller provides the buyer.
D) As a record of when work elements are assigned to individuals.