@matuzo
I use method C, so things are even clearer (especially when debugging):

a {
display: flex;
}

@media (max-width: 1023px) {
a {
flex-direction: column;
gap: 1rem;
}.
}

@media (min-width: 1024px) {
.a {
flex-direction: row;
gap: 2rem;
}
}