If thep-value for a one-tailed test is 0.019, then the null hypothesis

may or may not be rejected, but there is no enough information to answer this question.

can be rejected at a significance level of 0.01.

can be rejected at a significance level of 0.10.

would be rejected or not rejected depending on the value of the statistic and the critical value.

would be rejected or not rejected depending on the value of the statistic (the observed value).