Analysis of radial cracks from three impacts revealed that cracks from A stopped at cracks from Z. Cracks from Z stopped at cracks from B. Which is the correct order of impacts from first to last?

I think that the correct order of impacts would be first a, then z, then b because the radial cracks at a were cut off by the cracks at z and the cracks at z are cut off by the cracks at b so in other words I think that when radial cracks are cut off by another series of cracks, the other series of cracks postdates the first set of cracks (impact)