Regarding bronchial muscle tone, which statement is correct?

    1. Beta 2 adrenoreceptor stimulation and muscarinic cholinergic stimulation both decrease bronchial tone
    2. Beta 2 adrenoreceptor stimulation and muscarinic cholinergic stimulation both increase bronchial tone
    3. Beta 2 adrenoreceptor stimulation decreases tone and muscarinic cholinergic stimulation increases bronchial tone
    4. Beta 2 adrenoreceptor stimulation increases tone and muscarinic cholinergic stimulation decreases bronchial tone