In the two sample t test, deviation from the Normal distribution by the data may seriously affect the validity of the test if: (a) the sample sizes are equal; (b) the distribution followed by the data...

In the two sample t test, deviation from the Normal distribution by the data may seriously affect the validity of the test if:

(a) the sample sizes are equal;

(b) the distribution followed by the data is highly skewed;

(c) one sample is much larger than the other;

(d) both samples are large;

(e) the data deviate from a Normal distribution because the measurement unit is large and only a few values are possible.