A consent decree purporting to create a gift does not fall within Section 17(1)(a) (which covers non-testamentary instruments, not court decrees), but it is also not exempt under Section 17(2) — the exemption under 17(2) applies to decrees that merely record a pre-existing transaction, not one that itself operates to create a gift. Option C is wrong because Section 15(2) does not exist in this Act. Option D incorrectly grants exemption under 17(2) to such a decree.