(单选题)
颈动脉三角的境界是
A胸锁乳突肌前缘,二腹肌前腹,下颌骨下缘
B胸锁乳突肌前缘,二腹肌前腹,肩胛舌骨肌下腹
C胸锁乳突肌前缘,二腹肌前腹,肩胛舌骨肌上腹
D胸锁乳突肌前缘,二腹肌后腹,肩胛舌骨肌上腹
E胸锁乳突肌后缘,二腹肌前腹,肩胛舌骨肌上腹
A胸锁乳突肌前缘,二腹肌前腹,下颌骨下缘
B胸锁乳突肌前缘,二腹肌前腹,肩胛舌骨肌下腹
C胸锁乳突肌前缘,二腹肌前腹,肩胛舌骨肌上腹
D胸锁乳突肌前缘,二腹肌后腹,肩胛舌骨肌上腹
E胸锁乳突肌后缘,二腹肌前腹,肩胛舌骨肌上腹