Why is the extrapolation of the Λ vs c curve back to zero concentration unreliable for weak electrolytes in obtaining Λθ?

The answer is the first option just took the test

Aseasonal prevailing wind in the region of south and southeast asia, blowing from the southwest between may and september and bringing rain (the wet monsoon ), or from the northeast between october and april (the dry monsoon ).

Naoh + hbr -> nabr (salt) + h2o ca (oh)2 + 2hbr - - - > ca (br)2 + 2h2o