def oi(): return int(input())
def os(): return input()
def mi(): return list(map(int, input().split()))

m = 998244353

def f(A, B):
    if (A < 0):
        return 0
    q = A//B
    r = A % B
    q %= m
    r %= m
    return ((q*(q-1)//2) % m * B % m + q * (r+1) % m) % m

T = oi()
for i in range(T):
    N, M, L, R = mi()
    ans = (R-L+1) % m
    ans += f(R, N-1)
    ans -= f(L-1, N-1)
    ans += f(M-L, N-1)
    ans -= f(M-R-1, N-1)
    ans %= m
    ans += m
    ans %= m
    print(ans)