Yes. Set multisampling in the method Graphics_PreparingDeviceSettings

private static void Graphics_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
{
	 Device.PresentationParameters.MultiSampleCount = 0;
}

When you don't explicitly set multisampling the render target constructor uses the system value. And the correct place to setting the multisampling count is this method.

Yes. Set multisampling in the method Graphics_PreparingDeviceSettings

private static void Graphics_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
{
	 Device.PresentationParameters.MultiSampleCount = 0;
}

When you don't explicitly set multisampling the render target constructor uses the system value. And the correct place to setting the multisampling count is this method.

Yes. Set multisampling in the method Graphics_PreparingDeviceSettings

private static void Graphics_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
{
	 Device.PresentationParameters.MultiSampleCount = 0;
}