I think the primary ______ factor is there's been so much absence lately.A. contributingB. developingC. increasing

本题考察形容词辨析。根据句意，“primary _ factor”需表达“主要的促成因素”。A项“contributing”意为“促成的”，符合句意，表示“导致缺勤的主要因素”。B项“developing”和C项“increasing”均不符合语境，无法体现“导致原因”的含义。最终，A项最贴合句意。