What statistical test should I use here?

A team of psychologists have developed an experimental treatment program for a learning disorder with the expectation that the treatment would enable recipients to score higher than before on a test of learning ability. To test the treatment, they randomly select a pool of 30 volunteers who have been diagnosed with the disorder and who have volunteered for the treatment program. Following treatment, the participants are retested on the learning ability test and their scores compared to earlier scores.

I need to know what statistical test to use here, but I can't figure out if this is a t-test, z-test, ANOVA one-way? I just can't figure it out at all, any help is appreciated thank you!!